This invention relates generally to a nailable floor construction, and more particularly to such a construction as having closed bottom serpentine nail-receiving grooves formed in such a manner therein as to render the flooring self-supporting and to prevent the entry into the grooves of any dirt, debris or heat from fire from below the flooring.
A wide variety of flooring constructions are known as having different types of nail-receiving grooves therein for the reception of nail fasteners held in place as they are deformed during insertion. The grooves are contoured to facilitate such deforming of the nail fasteners although, because of their particular construction, the groove structure is incapable of supporting the flooring without the provision of a central longitudinal support element which, quite obviously, only adds to the cost and complexity of such flooring constructions. On the other hand, nailable flooring units have been devised without the use of central support members, although the structural integrity and the reliability of such units remains doubtful. Both general types of flooring units thus far discussed, moreover, have nailing grooves open to the space therebelow. Hence, when such nailable constructions are used for example as the flooring for a railroad box car, the open bottom nailable grooves present a hazardous situation if fire were to break out beneath the flooring. The heat and even the flames themselves could easily penetrate the flooring through the open grooves and severely damage the contents supported thereon. Moreover, the box car contents lying directly on the nailable flooring are subject to contamination from the space therebelow as dirt, debris and other contaminants easily enter the interior of the box car through the open grooves.
Nailable surface construction units are nevertheless known as having nailable grooves with closed bottoms. However, the grooves are so designed as to merely crimp the nail fasteners upon insertion, rather than to more positively anchor the nail fasteners in place as by deforming.